Swiss brand Kuhn Ricon has made a trademark of brightly colored novelty knives, including fruit-specific ones. But there’s also some deceptively serious functionality behind these cartoonish, carbon steel implements. The Citrus knife, for instance, is a three-in-one tool, with paring knife, zester and scorer wrapped in a compact, foldable profile; while the 11″ Watermelon knife, which comes paired with a protective sheath, is sharp enough to slice through melon rind as the tiny seed-shaped perforations help trap pesky seeds. That’s sharp thinking.